Internal surface treatment tool for duct - has tool holding trolley travelling longitudinally and is fitted with rotatable arms

摘要

The tool holder is supported on a frame having two angled members (13) and a horizontal plate (22). The frame is supported on angled wheels, (14) enabling the frame to travel down the duct. The frame supports a central hub which carries three rotating arms (15). The arms are spring loaded and fitted with rollers (60) travelling radially in the duct. The arms are driven through a gear train (33) and (34) and carry the necessary brushes, or spray nozzles or sanders, which can be adjusted from the surface. Paint is fed through internal passages to the tools.